gh-update-os

#!/bin/bash
# A duplicate of gh-update-os, except this one serves the purpose of applying the actual update
if [[ $EUID -ne 0 ]];
then
    exec pkexec --disable-internal-agent "$0" "$@"
fi
argdata=$1
ready_watcher=/tmp/gh-update-ready-to-deploy
downloadpath=/home/.gh_offload/updatecontainer
# We assume we entered this step only after confirming that we are okay to continue.
verintg(){
    echo "Starting to update..."
    if [[ -f "${installcontainer}" ]]; then
        CURR_SHA=$(echo $(sha256sum ${installcontainer}) | awk '{print $1}')
        if [[ "${CURR_SHA}" == "$(cat ${installcontainer}.sha256)" ]]; then
            echo "Validity matches. Continuing to next step."
        else
            rm -rf ${downloadpath}/${OS_TAG_NAME}
               echo "Verification failed. Download contents erased."
               exit 1
        fi
    else
        echo "Unable to find update container. (Download issues?)"
        exit 1
    fi
}

cleandeployments(){
    DEPLOYMENTS_PATH=$(btrfs subvolume list /gh_root | awk '{print $9}')
    CURR_DEPLOYMENT=$(mount | grep subvol=/rootfs | sed 's/.*subvol=\///g' | sed 's/)//g')
    for deployment in $DEPLOYMENTS_PATH;
    do
        if [[ "$CURR_DEPLOYMENT" == "$deployment" ]]; then
            echo "Ignoring deployment $deployment, as it's currently used."
        else
            echo "Removing unused deployment $deployment..."
            btrfs subvolume delete /gh_root/$deployment
        fi
    done
}

finalizeupd(){
    mkdir -p ${installpath}
    mount -t btrfs -o subvol=rootfs/${OS_TAG_NAME} -L gh_root ${installpath}
    arch-chroot ${installpath} gh-readonly disable
    arch-chroot ${installpath} gh-grub-update
    arch-chroot ${installpath} gh-readonly enable
    umount -l ${installpath}
    echo "Cleaning up..."
    rm -rf ${downloadpath}/${OS_TAG_NAME}/
    echo "Update complete."
}

beginupd(){
    # Decompress update container
    echo "Decompressing update container..."
    zstd -df ${installcontainer}
    echo "Removing the unused snapshot..."
    cleandeployments
    echo "Installing snapshot..."
    btrfs receive /gh_root/rootfs/ < ${installfile}
    finalizeupd
}

if [[ -f ${argdata} ]]; then
    if [[ -f "${ready_watcher}" ]]; then
        source ${argdata}
        installcontainer=${downloadpath}/${OS_TAG_NAME}/${OS_TAG_NAME}.img.zst
        installfile=${downloadpath}/${OS_TAG_NAME}/${OS_TAG_NAME}.img
        installpath=/tmp/mounts/${OS_TAG_NAME}
        verintg
        beginupd
    else
        echo -e "Arg data was found, but ready to update sentinel was not found.\nAre you sure that the update container download was completed?\nTry running gh-update download-update to verify container integrity again."
    fi
else
    echo "No deploy arguments set."
    exit 1
fi